1. Field Of The Invention
This invention relates to a removable implanted device, and more particularly, to a ultrasound sensor for measuring blood flow which can be implanted, then removed from the patient without reopening the implant wound.
2. Description Of The Related Art
The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is "prior art" with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. .sctn.1.56(a) exists.
U.S. Pat. No. 3,661,146, entitled "Transducer Arrangement For Measuring Blood Flow", issued May 9, 1972 to Peronneau, is directed to a transducer for measuring the speed and flow of blood. The transducer is fixed to the vessel with a band of dacron which is sutured shut. This device does not allow for removal without reopening the wound.
U.S. Pat. No. 4,313,448, entitled "Myocardial Sutureless Lead", issued Feb. 2, 1982 to Stokes, is directed to a device which anchors itself in tissue using a barbed end. This device does not utilize sutures in conjunction with a wire to allow for removal without reopening the wound.
U.S. Pat. No. 4,355,643, entitled "Vacuum Cup Doppler Flow Transducer And Method For Using Same", issued Oct. 26, 1982 to Laughlin, is directed to a device which uses a suction cup to create a vacuum, and thereby attach the device to the vessel.
U.S. Pat. No. 4,541,433, entitled "Cardiac Output Monitor", issued Sep. 17, 1985 to Baudino, is directed to a device which uses a pair of fixation wires, which puncture the vessel and secure the instrument to the vessel.
U.S. Pat. No. 4,671,295, entitled "Method For Measuring Cardiac Output", issued Jun. 9, 1987 to Abrams, is directed to a device which does not require surgery. This device is inserted through the nasal or oral cavity.
U.S. Pat. No. 4,722,347, entitled "Apparatus For Measuring Cardiac Output", issued Feb. 2, 1988 to Abrams, is similar to U.S. Pat. No. 4,671,295.
U.S. Pat. No. 4,823,800, entitled "Implantable Ultrasonic Probe And Method Of Manufacturing The Same", issued Apr. 25, 1989 to Compos, is directed to a device which may be removed without a complex procedure.
U.S. Pat. No. 4,915,113, entitled "Method And Apparatus For Monitoring The Patency Of Vascular Grafts", issued Apr. 10, 1990 to Holman, is directed to an implantable device which is anchored to the vessel using a collar (see FIG. 2). This reference is not considered anticipatory or suggestive of the proposed invention.
U.S. Pat. No. 4,917,115, entitled "Pacing System And Method For Physiological Stimulation Of The Heart Utilizing Doppler Means", issued Apr. 17, 1990 to Flammang, is directed to a cardiac pacing device.
U.S. Pat. No. 4,926,875, entitled "Implantable And Extractable Biological Sensor Probe", issued May 22, 1990 to Rabinovitz, is directed to a probe body 10 which includes a doppler transducer to sense blood flow, and which is wrapped around the vessel and secured using suture 34 and release wire 28 (see FIG. 1, 1b). To release the device wire 28 is pulled back, releasing suture 34 and allowing the probe 10 to unwarp. The device is then gently pulled out of the patient without surgery.
U.S. Pat. No. 4,947,854, entitled "Epicardial Multifunctional Probe", issued Aug. 14, 1990 to Rabinovitz, is directed to a implanted device which measures blood flow velocity and muscle thickening with two sensors.